#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
    int a,b,c;
    double ar,s,zhou;
    scanf("%d %d %d",&a,&b,&c);
    if(a+b>c && a+c>b && b+c>a)
    {
        zhou = a+b+c;
        s = zhou/2;
        ar=sqrt(s*(s-a)*(s-b)*(s-c));
    }
    else
    {
        printf("These sides do not correspond to a valid triangle");
        return 0;
    }
    printf("area = %.2lf; perimeter = %.2lf",ar,zhou);
}
